Engine Replacement

I have a Mazda 626 2002 with 129,000 miles on it. Took it to the mechanic today. He stated that there is a piston rod knock and that I have to look at replacing the engine. He can get an engine w/34,000 miles for about $700.00. All in, including replacing the clutch, I am looking at about $2000.00.

My questions

1. Is it worth it

2. do secondary engines typically last- we are trying to keep the car for another year or two…

thank you for the help

What did you take it to the mechanic for? Let’s be sure the mechanic is right before we worry about replacing the engine.

We cannot guesss whether it’s worth it without a good idea of the condition of teh rest of the car and its history.

If the secondary engine was well maintained and is in good shape it’ll typically last. If your rod knock is because you neglected the engine in some way, like neglecting the oil, then the new one if treated in a similar fashion probably won’t last either.

Either way, I’d get a second opinion before making any decisions…unless, of coure, you know it’s bad because you were neglecting it.

I took the car to the mechanic, because of a high pitched noise and sluggishness going up hill, something it did not have before. It sounds like a rattle, but of course I am no car expert…

The car is in excellent shape inside and out and we have been diligent about oil changes, tune-ups and whenever something seems not right, I take it in.

We were more surprised by the decline in the engine, since we have always had Mazda’s and had very good luck with their mileage and endurance…

This does not sound like typical rod bearing knock to me. Definitely get a second opinion before proceeding. You might just have simple pinging.

You could also have a loose spark plug which is allowing combustion gasses to escape out past it. This effectively deletes a cylinder from the engine, which would cause a loss of power, and it makes weird noises as the plug and wire bounce around during the cycles.

Here is a quicktime movie of the engine, with noises…

If this rattle only exists while going uphill then I second mountainbike about pinging.
If this is the case then it may be nothing more serious than an EGR system fault and that certainly does not mean another engine is needed.

it happens all the time. This was taken in my driveway, idling…

I discovered today that turning on the a.c. decreased the noise. Am hoping that it is a bearing in the air compressor

It’s possible. If your AC is driven by a seperate belt, the easy way to test your theory would be to remove the belt and see what happens. If it isn’t if it’s on a serpentine belt, you could always open the hood, have a friend engage and disengage the AC, and listen to where the noise seems to be eminating from.

If it turns out to be related to the A/C compressor, then in addition to having the compressor replaced, you also need to replace your current mechanic.

If this mechanic is telling you to replace the engine, he is either incompetent or he is a thief. I don’t know about you, but I don’t want either category of mechanics working on my car.